Common Traits (Pick any that apply to your custom Dinosaur)
Armor: Number of Armor Dice the Dinosaur adds, typically 1-6
Damage: Most Dinosaur attacks do Str. +1-+3 Lethal. Bites are Difficulty 5, Stomps, Tail Swipes, Claws, Horns are Difficulty 6, Charges & other attacks are Difficulty 7. A Dinosaur that manages to perform a running charge inflicts Double Damage.
Senses: Most Dinosaurs have at least one Acute Sense, & several may have senses entirely unexpected. All perception rolls are -2 Difficulty, & if deemed particularly acute, you should double there Perception + Alertness Dice Pool for that particular sense.
Camouflage: A Dinosaur with Camouflage may add +3-5 dice to Stealth & Hide rolls.
Flight: The Dinosaur flies at a speed roughly double human running speed.
Speed: Most Predatory Dinosaurs run about 1.5 times faster than a man. If a Dinosaur is deemed particularly fast, it may gain an extra action per turn, up to a maximum of 3.
Venom: Anyone injected with the Dinosaurs venom must roll Sta.+ Endurance (Diff: 6-9 as desired). Subtract any successes from a Potency number (typically equal to Dinosaur’s Stamina). The Potency number determines how much unsoakable, Lethal Damage the target will suffer, accumulating at a rate of 1 level per turn, minute, or hour as desired. Multiple injections are cumulative.
Infection: An infected attack should be given a potency number (1-5). Every time someone is exposed, Roll the potency number in dice against a difficulty of the target’s Stamina + Endurance. Even one success is enough to begin infection. Characters infected will take a number of dice Bashing or Lethal damage per incubation period (varies per infection). Some terminal diseases cannot be handled by mortal bodies, & will have indefinite infection periods. Medicine checks versus the Disease Potency +4 may reduce the severity of the disease (Lethal to Bashing), or shorten the infection duration if already reduced to Bashing (successes reduce duration).
Constrictor: Upon grappling a target, this Dinosaur deals Lethal Damage from sustained holds.
Aquatic: No penalties for movement underwater; may hold breath for an hour if not totally aquatic.
Screech: By screeching in alarm or while hunting, the dinosaur attracts any others of it’s kind in 1 mile.
Swallow: The Dinosaur may use it’s bite attack as a free Grapple (successes to bite are treated as Grapple successes).
Sprinter: The Dinosaur gains +10 to initiative & doubles running speed for the beginning of combat.

Well, to date we have had Infectious Flesh Eating Zombies patterned after the Zombie Survival Guide, by Mel Brooks son. The Virus (Solanum) produces similar zombies & is an established house game fact. However, you can easily proceed with your method as a mutation or derivative (intentional or otherwise). I recommend you do; makes for unique games.

Infection: Upon being infected, the victim takes 1 Lethal Damage per hour, eventually dying when they drop below Incapacitated. Decide how much time it takes for re-animation to occur. I recommend a short time, as you will want to keep the action high & you have allowed for a "cure", meaning the period of seeming death is probably rather short. Decide how exposure works. I recommend automatic infection upon blood contact, & a Stamina + Endurance roll (Difficulty: 8) for being exposed to the areosol agent. Maybe higher, depending on how prevalent you want it to be. Magical healing will generally heal Damage from the disease but will not cure the infection itself, thus only allowing for more time.

Zombie Stats: These reflect a mostly intact quasi-dead zombie, the sort which might be "cured"

Zombies are immune to any mind altering effect, as well as any effect that must target a living thing.

Zombies attack by Grappling, Slamming, or Biting When you run them, bear in mind that the Difficulty to attack is reduced by -1 for flanking, & -2 for attacks from behind. Characters with more balls than sense will swiftly be eaten by a horde of even weak zombies.

Grapple: Dex. + Brawl, Difficulty: 6. If you are Grappled, you may not take other actions (punching, shooting, stabbing, dodging, etc.) until you break free. A zombie only needs one success to grab you in this way. The grappled may roll Str. or Dex. + Brawl (Difficulty: 6) each action to break free, needing as many successes as the Zombie scored to grapple him in the first place. Multiple zombies pool there successes for this purpose. Zombies typically Bite after a grapple, in the next round.

Bite: Dex. + Brawl, Difficulty: 5, Damage: Str. Lethal. Zombies must grapple before attempting to bite in the following round.

Remind players that they are splitting dice pools if they are running & shooting at the same time. This will make there shots largely ineffective. Make sure they write down exactly how many bullets they've got. You'll find they run out quick. Make sure to enforce that. Zombies will not dodge, & as it takes a lot to put them down, they rarely need to.

Example: The Samurai faces a horde of 12 zombies. Roll initiative. Almost certainly, he goes first. As his first action, he strikes at a zombie & hits, dealing a pile of Lethal Damage to the Zombie. The zombie rolls Soak (at 6), no doubt taking damage but not feeling pain. Unless he kills it outright, all the zombies in reach (about 4-5) attempt to grapple. Unless he has held back dodge dice, at least one should succeed. Remaining zombies circle looking for an opening.

Round 2: The samurai (who should make a Courage roll to not freak out) attempts to break free. Lets say he makes it. Now he has all the zombies he just got away from grab at his legs, as well as even more zombies grab him from all sides. Again, he is grappled.

Round: 3: Repeat round 2 until he fails to break the cumulative grip of the zombies. As soon as a grapple is held for 1 round, all zombies begin biting, dealing small amounts of Lethal Damage, which mortals cannot generally soak.

Xenomorph Life
The species of aliens known as Xenomorphs live various stages of life. They are organized into Hives, with the Queen being the absolute head. She lays thousands of eggs in a birthing chamber. Drones protect the Queen and procure life forms for the eggs to incubate in. In the darkest reaches of space live Queen Mothers, true giants of the race. The average Queen Mother is even larger than a Queen and is as fast as a Drone. Queen Mothers rule over huge numbers of separate Hives, and their personal Hive is full of the largest of Drones. A Queen Mother can only be born of an alien ingesting Royal Jelly from the Hive of an existing Queen Mother.

The Xenomorph life cycle is thus: an egg hatches a small alien, often referred to as a "facehugger" (known scientifically as an ovipositor). This critter attaches itself to the face of a living being and implants an embryo inside the torso. This embryo gestates for 12 to 48 hours before ripping and chewing its way out. The resulting alien takes many DNA traits from its host. Careful observation can reveal the nature of the animal an alien spawned from. These young aliens grow to full maturity within a few hours and begin acting upon their instincts. If they are part of a Hive, they will begin gathering living beings to impregnate. If there is no Hive, they will begin killing every living thing they find. If there is no Queen, one of the implanted aliens will develop as one, or a Drone will evolve into a Queen.

All "facehuggers" look the same, spider-like beings with a long tail, and they can impregnate a large variety of beings. The films show bugs born of human and dog hosts, and the books tell of a Hive born of rhino-sized herbivores. Aliens can be birthed from any warm-blooded animal large enough to contain a gestating alien. This rules out cats, bats, rats, and other small animals. Humans, dogs, cattle, sheep, moose, rhinos, tigers, gorillas, etc., are all fair game. Aliens take some of their genetic make-up from their host. Thus a biped host will produce a biped bug, etc. Once implanted, the alien radically alters the host's DNA so that it will be suitable for the alien to incubate within. This amazing ability is what allows the Xenomorphs to spawn from such a variety of animals. Aliens cannot gestate in plants, but it is not known if they can birth from reptiles or other more exotic creatures.

Drones and Queens share certain characteristics, they have a shiny black carapace over their entire bodies, thus, the resemblance to insects. This carapace is silicon based and harder than steel. Their green blood is a super acid (perhaps a type of hydrofluoric acid) and can eat through flesh, armor, steel, plastic, glass, and just about anything exposed to it. Xenomorphs have no eyes, so bright lights and absolute darkness have no affect on them. It is theorized that they may "see" using psychic vibrations. This psychic sense allows them to sense emotions such as fear and pain. Each emotion is seen as a color to the aliens. Also, their visual awareness extends in a 360 degree arc around their heads. The mouth of the alien is unique: a fanged maw that contains a toothed tongue within. This tongue is able to extend from its face about a foot and creates a puncture motion when it bites, enabling the alien to pierce armor.
All observed aliens have had tails which seem to have something to do with their communication abilities. They are able to slap with them, and the Queen can use hers to stab like a large blade. The aliens are exceptional climbers, even able to suspend themselves upside down from ceilings. It is unknown if a surface can be too smooth for them to climb. Unfortunately, the Drones possess a devious intelligence, the Queens even more so. All aliens have tremendous cunning and are experts at hunting and ambushing. As an example, to escape a cell, the aliens kill one of their own in order to make it bleed. The blood eats through the floor, and out they go. They are smart enough to plan and lay traps.

The Xenomorphs do have sexes; however, the average Drone is neuter. Those who do have a sex are generally female. Males do occasionally get the chance to mate with the Queen but are killed soon after. All Queens are, of course, female. There are no Kings in the Xenomorph society. It is important to note that Queens are born pregnant and do not need males to perpetuate the race.

The Hive
Xenomorphs are social creatures who live and die for the Hive, with no concern for their own safety. A Hive will swarm over intruders until one or the other is completely annihilated. No retreat, no surrender.
The Hive is marked by a horrible stench, reminiscent of rotting eggs and meat. Aliens secrete an enzyme that is used to create their Hive. They mold it in a pattern much like the inside of a rib cage. This enzyme is brittle, and can be broken fairly easily (Strength roll, difficulty 6). The inside of the Hive is very warm and humid, and in great numbers Hives can alter the weather systems of an entire planet. After the alien infestation on Earth, freak thunderstorms and intense heatwaves were found throughout the world.
The Hive generally encompasses a large area with the Queen's chamber of eggs and Drones in the center. Along the walls leading to the chamber, living beings are bound to await impregnation. The bodies will be suspended in the enzyme (which is much more difficult to break when bound by it, Strength roll, difficulty 9). Also in the egg chamber is the sac of Royal Jelly (see below). A typical Hive will have huge Drones (add 1 to Strength and Stamina) protecting the Queen and eggs. Also note that the Xenomorphs leave the bodies of the incubators hanging in the Hive. When an area gets full, they simply move the birthing process elsewhere. This results in chambers "decorated" with the grisly remains of their prey.
Aliens are intent on breeding. In one case, aliens captured a ship full of humans, but rather than lay eggs in all of them, they left two alive, one male and one female, and forced them to mate. In order to ensure the propagation of future hosts, aliens feed their captives; however, their diet consists of the rotting flesh of those already used to birth aliens. They force this repulsive meal down the throats of captives. Heaven help any survivors of such an imprisonment, derangements are definitely in order.

Xenomorph Psychology
The aliens do have individuality; however, thinking and existing in such a state is terrifying to them. They prefer to live with others of their kind in constant telepathic contact with one another. The thoughts of each individual alien is broadcast to the other Drones and the Queen for approval. Thus, any ideas or knowledge is instantly sent to the entire Hive.

Aliens are completely devoted to the Hive, or creche, as they refer to it. To protect the creche and serve the Queen is all that gives meaning to the lives of the Xenomorphs. A Drone will sacrifice itself for the Hive without a moment of hesitation.

The Queens continuously transmit feelings of intense love and belonging. A Drone cut off from these feelings will suffer from a loneliness humans cannot possibly understand. Such an alien will try to return to the creche in any way possible. It is not known how far a Queen can broadcast such emotions, but the signal from a Queen Mother was strong enough for some humans on Earth to sense all the way from Hiveworld.

Unfortunately, these feelings of love do not extend to species outside their own. Everything else is viewed as to its benefit to the creche, either as hosts or as food. They have no concepts of peace or co-existence. To them, only the Xenomorphs should survive. The aliens have no dreams of conquest or any other such motivation, living only to decimate all other races.

One of the most terrifying aspects of the Xenomorphs is their racial memory. Once something is transmitted to the Queen, all of her future offspring will remember it. For this reason the Xenomorphs became progressively more difficult to deal with throughout the films. All aliens in the second through fourth films were descendants of the same Queen. Thus, all remembered every encounter they had with humans and how to deal with them. An entire Hive learns at the same time.

This kind of intelligence makes the Xenomorphs even more dangerous than previously believed. A strategy or trick that worked on one alien won't work on any of the others from the same Hive. In all likelihood, good ideas will be used right back upon their enemies. Few species could stand up against such creatures for long, and so far mankind has been lucky.

Royal Jelly
The mysterious substance known as Royal Jelly is found only in the heart of the Hive, in the chamber of the Queen. It is this substance that is fed to aliens to cause them to grow into Queens when it is time to expand the colony. The uses of the Jelly are tremendous to humans as well.
After Earth was reclaimed from the Xenomorphs, scientists began studying the Jelly and its uses. The result was a drug called Xeno-Zip (referred to as Fire in slang), produced by the chemical company Neo-Pharm. Upon taking a capsule of this, human senses, abilities, and endurance were heightened dramatically. Of course, the military decided to use it for "super soldier" experiments.
Unfortunately, Fire has many drawbacks. First of all, it is the most addictive drug ever designed. It takes an iron will to be able to stop taking the drug after trying it even once. Also, the threats of overdose are very serious. A person being burnt up by Fire is a terrifying sight. The instincts of rage become so great that a person will immediately attack every living creature around him until either himself or the object of his wrath is destroyed. No one has ever recovered from an OD on Xeno-Zip.
A person taking a normal dose of Xeno-Zip adds one Die to all dice pools. An extra action may also be taken every turn until the drug wears off (1 hour minus (Stamina minutes)). He or she gains all the benefits and drawbacks of Acute Senses of Sight, Hearing, and Touch. When someone overdoses on the drug, he gains all of the above, plus all Health Levels are doubled. However, the poor person will attack any living being he can find until he is destroyed (as Frenzy), or he dies when consumed by Fire (same duration as above). A person will not always go on a killing spree but will still push himself beyond the brink. For example, a runner overdosed during the Goodwill Games and ran himself through a metal grate. Needless to say, it was fatal.

Hiveworld
Hiveworld is the home of the aliens living in this quadrant of the galaxy. This is not the homeworld of the Xenomorphs as a whole, only the ones encountered by man. The planet orbits the star Achilles II and is the fourth of ten planets. It is planet G-435, a class M planet covered in a shallow, toxic ocean. The clouds are thick and somewhat poisonous to humans. Man can live for only a short time without a environmental suit of some kind. The greenhouse effect is rather intense, with a humid, steamy atmosphere the result. The ground is flat and rough, with fungus-like plants growing from the noxious water. The winds are brutal and the gravity is somewhat higher than on Earth.
The planet is ripe with seismic activity; earthquakes are common and volcanos dot the landscape. There is very little to welcome visitors, and the inhabitants are even worse. Not only does the planet swarm with Xenomorphs, but other predators prowl the barren land. Massive, winged reptiles patrol the skies in search of prey. Their wingspans are at least twenty feet across and their mouths are huge and lined with sharp teeth. Interestingly, these creatures don't hunt the Xenomorphs.

At one time, the planet was host to two huge alien Hives, home to thousands upon thousands of aliens. The two Hives were engaged in a genocidal war (see Red Ants below) when visited by humans. As a gift, the humans left a nuclear bomb in each Hive, blowing them from the face of the planet. It is unknown if Xenomorphs from either race survived past the 22nd century on G-435; however, given the aliens' proven ability to survive, count on it.

Abilities and Characteristics
Acidic Blood: The green blood of an alien can eat through most anything, including wood, metal, plastic, flesh, glass, and polymers. When wounded, their blood tends to spew from their bodies. Anyone within five feet of an alien when it is wounded is splattered with blood. One point of blood is spewed per wound level. Those sprayed must try to make a Dexterity + Dodge roll with a difficulty of 8. Each success negates one blood point's worth of acid exposure. Each blood point inflicts 1 level per degree of acid exposure (up to 3) dealing aggravated damage at a potency of 5. The blood oxidizes soon after death, making it harmless. Note that using a melee weapon against an alien is suicidal. Not only does one risk being sprayed with blood, the acid will destroy most weapons in one turn.
The novels make an interesting point about combating the Xenomorphs. A body shot tends to cause the aliens to spew forth lots of acid as above. However, the head does not spurt as badly. Thus, a shot to the head only spews a blood point for every two wound levels inflicted. A common combat strategy humans have learned in the Alien-Earth War is to shoot at the knees or the head of the aliens so blood spray is minimal. Once an alien has its legs blown out from under it, it is much easier to shoot in the head. In other words, aim low.

Acidic Spit: The Xenomorphs possess the ability to spit acid distances up to 15 feet. This spit is not nearly as corrosive as their blood but is still extremely dangerous. The acid inflicts one level of exposure on a Dexterity + Spit roll, difficulty based on cover of the target, etc.

Birthing: Aliens rip their way out of their hosts. They do this in one turn, causing a horrendous mess that is fatal to normal humans and animals.

Camouflage: Within a Hive, the bugs blend in almost perfectly with their secretions, which makes them very difficult to spot (Perception + Alertness roll, difficulty 8). Also, the aliens are invisible in the infrared spectrum.

Carapace: The hard silicon exoskeleton of the bugs gives them an armor rating of 3. This only applies to firearms and melee weapons, not fire and cold. The weapons used in the novels and films are carbines which fire 10mm armor piercing exploding bullets. Smaller, less powerful rounds literally bounce off of the Xenomorphs. It is not unreasonable to assume that anything less powerful than a 9mm round will not even have a chance to harm an alien (this would include .22, .25, and .32 rounds) unless shot inside the mouth. Aliens may soak Bashing & Lethal with Stamina at Difficulty: 6, but may only use Carapace to soak aggravated wounds.

Climbing: An alien can climb all but the slickest of surfaces. This includes the ability to hang suspended from walls and ceilings. Like insects, they don't seem to ever tire from "hanging on."

Communication: Aliens communicate through a kind of psychic process that uses an organ in their cranium. This communication can be picked up on radio waves but is mostly indecipherable. In theory, a psychic can pick up these signals as well but is unlikely to understand them. It might be possible to disorient a group of aliens with a radio set to the proper frequency. These communications can also cause severe nightmares in nearby humans. During the early days of the Alien-Earth War, if people were having nightmares about aliens it was a good indication of a nearby nest. In fact, some people could sense the calling of the great Queen Mother from another planet in this galaxy. Their dreams were of intense feelings of love and belonging, like they were being summoned by their mother. This call was used by humans to lure aliens into a nuclear deathtrap.

Cunning: Aliens like to stalk and ambush and are sly enough to cut power lines and the like. Also, they often make use of unexpected openings. For example, in Aliens, they come in over the ceiling tiles. In Alien Resurrection, they lay a trail of weapons like bread crumbs down a dead-end corridor.

Extraordinary Senses: Aliens have no eyes but can "see" in a 360 degree arc around their heads. They can smell and hear at least as well as the average human, but it is unknown if they have a sense of taste. They feel pain. It is assumed that they move with a kind of psychic sonar, much like a bat, but this is yet to be proven. In Alien Resurrection (the novel), the aliens distinctly see color and movement, maybe as well as humans.

Ferocity: An alien has no fear. It will fight until you or it dies. It is also aggressive, and once a battle is joined, all of its Hive mates will charge as well. Also, they will put up a chase. In game terms, this means that the aliens never need to check Virtues to continue fighting.

Health and Healing: A Drone has as many Health Levels as an average human. A Queen has double that number, and a Queen Mother has three times as many! The "facehuggers" only have 5 health levels (OK, -1, -2, -5, Incapacitated). Aliens do not have the rapid healing abilities of many of the supernaturals in the World of Darkness. They heal at the same rate as humans.

Hive Mind: Drones often cannot exist for long outside the Hive. An imprisoned Drone will gradually become listless and lose a point of Willpower per week until they die. There are exceptions to this, the egg pods, the life span of which is unknown. However the same egg clutch that infected the Nostromo infected the colony, Hadley's Hope, on LV-426 a full 57 years later. A Drone that is away from a Hive, but is in a suitable habitat will evolve into a Queen and setup its own Hive.

Resilience: Xenomorphs can be burnt, fire does damage to them just like most living things; however, extremes in heat and cold don't seem to affect them. So, while fire is an effective weapon, molten lead is not. They also seem to be somewhat afraid of fire, if they are really afraid of anything. An alien can survive in the vacuum of space for an undetermined amount of time. Their blood superheats to keep the creature warm in the absolute cold of space. In Alien

Resurrection, a Xenomorph is sprayed with liquid nitrogen, causing the creature pain but no lasting damage. They apparently don't breath, or are able to store air in their bodies.

Swimming: In Aliens, one of the Xenomorphs swims up to Rebecca and captures her; however, it is unknown how long they can remain underwater. In Alien Resurrection the aliens show an amazing aptitude for swimming, being fast and graceful. One even jumped out of the water up to 15 feet. This is not surprising, as Hiveworld is covered in shallow water. If the aliens can truly exist without air, then there could be Hives entirely underwater.

Teeth and Claws: An alien has sharp spindly six-fingered claws that shred flesh and clothing easily. Although this damage is not aggravated, the bite of the alien does inflict aggravated damage.
Combat
Maneuvers
Difficulty
Damage